Question 1

Which of the following best describes the three basic ways hormones act on their target cells?

Accepted Answer

Hormones alter gene expression, change membrane permeability, and modify enzyme activity.

Question 2

A hormone is defined as:

Accepted Answer

A chemical messenger secreted by a cell or group of cells, transported in the blood to a distant target, and effective at very low concentrations.

Question 3

Which of the following statements about peptide hormones is correct?

Accepted Answer

Peptide hormones are synthesized as preprohormones, processed in the endoplasmic reticulum and Golgi apparatus, and released via exocytosis.

Question 4

Steroid hormones differ from peptide hormones in that:

Accepted Answer

Steroid hormones are synthesized on demand from cholesterol and are not stored in vesicles.

Question 5

Which equation correctly represents the half-life ($$t_{1/2}) of a $$hormone, given its rate constant $$k$$?

Accepted Answer

$$t_{1/2} = \frac{\ln 2}{k}$$

Question 6

A patient presents with high cortisol, high ACTH, and low CRH. Based on feedback loops, this condition is best diagnosed as:

Accepted Answer

Secondary pathology, with the abnormality in the anterior pituitary.

Question 7

Which of the following hormones is NOT a trophic hormone produced by the anterior pituitary?

Accepted Answer

Prolactin

Question 8

Which of the following best describes the mechanism of action for steroid hormones?

Accepted Answer

Steroid hormones bind to intracellular receptors, often affecting gene transcription and protein synthesis.

Question 9

Which of the following is an example of a permissive hormone interaction?

Accepted Answer

Thyroid hormone allows reproductive hormones to exert their full effect on development.

Question 10

Which two amino acids are precursors for amine hormones?

Accepted Answer

Tyrosine and tryptophan

Question 11

A patient is given exogenous cortisol. What is the most likely effect on endogenous ACTH and CRH levels?

Accepted Answer

Both ACTH and CRH levels will decrease due to negative feedback.

Question 12

Which of the following best describes the structure and function of a portal system?

Accepted Answer

A portal system consists of two capillary beds in series, allowing efficient transport of hormones from the hypothalamus to the anterior pituitary.

Question 13

Which hormone is secreted by the pineal gland, and what is its primary function?

Accepted Answer

Melatonin; regulates circadian rhythms and sleep-wake cycles.

Question 14

Which of the following is a correct example of a synergistic hormone interaction?

Accepted Answer

Glucagon, epinephrine, and cortisol together raise blood glucose more than the sum of their individual effects.

Question 15

Which of the following best explains why carrier proteins are required for steroid hormone transport in the bloodstream?

Accepted Answer

Steroid hormones are lipophilic and do not dissolve readily in plasma.

Question 16

Which scenario best illustrates a primary endocrine pathology?

Accepted Answer

A tumor in the adrenal cortex causes high cortisol, low ACTH, and low CRH.

Question 17

Which of the following best describes the process of down-regulation?

Accepted Answer

High hormone levels cause cells to decrease the number of receptors, reducing sensitivity.

Question 18

Which of the following is a correct example of an antagonistic hormone interaction?

Accepted Answer

Insulin decreases blood glucose while glucagon increases it.

Question 19

Which of the following best describes the cellular mechanism of action for peptide hormones?

Accepted Answer

Peptide hormones bind to surface membrane receptors, activating second messenger pathways for rapid responses.

Chapter 7: Hormones and Endocrine System – Guided Study Notes

Study Guide - Practice Questions